1. Field of the Invention
This invention relates generally to brake discs for motor vehicles, and more particularly, to a composite brake disc arrangement formed of two cast portions, a mounting portion and a brake band portion, the two portions forming a frictional interface.
2. Description of the Related Art
Brake discs that conventionally are formed of a combination of a mounting portion and a brake plate portion employ, in some known arrangements, a continuous skirt extending radially outward of the mounting portion, the continuous skirt engaging a brake plate portion (i.e., brake band). The mounting portion is sometimes referred to as a “rotor hat,” due to its raised central portion and a substantially cylindrical portion extending axially therefrom. This combination, particularly with a continuous skirt extending radially from the cylindrical portion and disposed axially distal from the central portion gives the general appearance of a hat. It is also known as the “mounting bell.”
In the known art, the engagement between the continuous skirt and the brake plate portion is achieved in a plurality of ways. One engagement method involves direct communication between the mounting portion and the brake plate portion, thereby forming a continuous product. In other known connection arrangements, fingers radiate radially inward from the brake plate portion and at connected by fasteners to the continuous skirt. The radially inwardly extending fingers can be formed integrally with the brake plate portion. In these known arrangements, the mounting portion and the brake plate portion are so firmly attached to one another that the operate as a single element.
It has been recognized that heating of the brake plate portion during manufacture and use in a motor vehicle will cause various forms of warpage and deformation, particularly including radial deformation. On known approach to alleviating this problem is to employ radially inwardly directed fingers, which are formed integrally with the brake plate portion, and communicate with the mounting portion. The fingers, however, are able to be displaced radially, thereby arguably enabling radial dilation of the brake plate portion so as to accommodate the radial deformation. There is no mechanism in the known arrangement that will reduce vibration during braking, notwithstanding that the mounting portion and the brake plate portion have a small measure of separation between them.
There is a need, therefore, for a brake disc arrangement that is characterized with increased dampening over conventional brake disc arrangements.
There is a further need for a brake disc arrangement that exhibits reduced deformation in response to thermal and mechanical loading during service in a motor vehicle, and during the manufacturing process.
There is additionally a need for a brake disc arrangement that is characterized with an overall reduced mass.